First occurrence of KPC-2-possessing Klebsiella pneumoniae in a Greek hospital and recommendation for detection with boronic acid disc tests

Abstract

To investigate the first KPC carbapenemase-producing Klebsiella pneumoniae isolate from a Greek hospital, including phenotypic methods to aid recognition of this resistance type. A carbapenem-resistant clinical isolate of K. pneumoniae was recovered from a hospitalized Greek patient. Detailed susceptibility testing was carried out by the agar dilution method. The isolate was screened by phenotypic and genotypic assays for the presence of various β-lactamases. Boronic acid disc tests were performed to show the ability of these tests to detect production of the KPC enzymes. The potential for conjugal transfer of carbapenem resistance was examined by biparental matings, plasmid analysis and PCR studies. The isolate possessed on the same self-transferable plasmid the KPC-2 carbapenemase and the SHV-12 extended-spectrum β-lactamase. Although the isolate did not produce an AmpC-type enzyme, the production of KPC-2 was associated with positive boronic acid disc tests using cephamycins and cefotaxime as well as cefepime and carbapenems as substrates. KPC-2-possessing K. pneumoniae clinical isolates seem to have been introduced in our region. Boronic acid disc tests using boronic acid in combination with carbapenems or cefepime may help the phenotypic detection of KPC enzymes and their distinction from plasmid-mediated AmpC enzymes.